Portable Vehicle Battery Jump Start Apparatus with Safety Protection and Jumper Cable Device Therefor

ABSTRACT

A handheld device for jump starting a vehicle engine includes a rechargeable lithium ion battery pack and a microcontroller. The lithium ion battery is coupled to a power output port of the device through a FET smart switch actuated by the microcontroller. A vehicle battery isolation sensor connected in circuit with positive and negative polarity outputs detects the presence of a vehicle battery connected between the positive and negative polarity outputs. A reverse polarity sensor connected in circuit with the positive and negative polarity outputs detects the polarity of a vehicle battery connected between the positive and negative polarity outputs, such that the microcontroller will enable power to be delivered from the lithium ion power pack to the output port only when a good battery is connected to the output port and only when the battery is connected with proper polarity of positive and negative terminals.

BACKGROUND OF THE INVENTION

The present invention relates generally to apparatus for jump-starting avehicle having a depleted or discharged battery. Prior art devices areknown, which provide either a pair of electrical connector cables thatconnect a fully-charged battery of another vehicle to the engine startcircuit of the dead battery vehicle, or portable booster devices whichinclude a fully-charged battery which can be connected in circuit withthe vehicle's engine starter through a pair of cables.

Problems with the prior art arose when either the jumper terminals orclamps of the cables were inadvertently brought into contact with eachother while the other ends were connected to a charged battery, or whenthe positive and negative terminals were connected to the oppositepolarity terminals in the vehicle to be jumped, thereby causing a shortcircuit resulting in sparking and potential damage to batteries and/orbodily injury.

Various attempts to eliminate these problems have been made in the priorart. U.S. Pat. No. 6,212,054 issued Apr. 3, 2001, discloses a batterybooster pack that is polarity sensitive and can detect proper andimproper connections before providing a path for electric current flow.The device uses a set of LEDs connected to optical couplers oriented bya control circuit. The control circuit controls a solenoid assemblycontrolling the path of power current. The control circuit causes powercurrent to flow through the solenoid assembly only if the points ofcontact of booster cable clamp connections have been properly made.

U.S. Pat. No. 6,632,103 issued Oct. 14, 2003, discloses an adaptivebooster cable connected with two pairs of clips, wherein the two pairsof clips are respectively attached to two batteries to transmit powerfrom one battery to the other battery. The adaptive booster cableincludes a polarity detecting unit connected to each clip, a switchingunit and a current detecting unit both provided between the two pairs ofclips. After the polarity of each clip is sensed by the polaritydetecting unit, the switching unit generates a proper connection betweenthe two batteries. Therefore, the positive and negative terminals of thetwo batteries are correctly connected based on the detected result ofthe polarity detecting unit.

U.S. Pat. No. 8,493,021 issued Jul. 23, 2013, discloses apparatus thatmonitors the voltage of the battery of a vehicle to be jump started andthe current delivered by the jump starter batteries to determine if aproper connection has been established and to provide fault monitoring.Only if the proper polarity is detected can the system operate. Thevoltage is monitored to determine open circuit, disconnected conductiveclamps, shunt cable fault, and solenoid fault conditions. The currentthrough the shunt cable is monitored to determine if there is a batteryexplosion risk, and for excessive current conditions presenting anoverheating condition, which may result in fire. The system includes aninternal battery to provide the power to the battery of the vehicle tobe jump started. Once the vehicle is started, the unit automaticallyelectrically disconnects from the vehicle's battery.

U.S. Pat. No. 5,189,359 issued Feb. 23, 1993, discloses a jumper cabledevice having two bridge rectifiers for developing a reference voltage,a four-input decoder for determining which terminals are to be connectedbased on a comparison of the voltage at each of the four terminals tothe reference voltage, and a pair of relays for effecting the correctconnection depending on the determination of the decoder. No connectionwill be made unless only one terminal of each battery has a highervoltage than the reference voltage, indicating “positive” terminals, andone has a lower voltage than the reference voltage, indicating“negative” terminals, and that, therefore, the two high voltageterminals may be connected and the two lower voltage terminals may beconnected. Current flows once the appropriate relay device is closed.The relay device is preferably a MOSFET combined with a series array ofphotodiodes that develop MOSFET gate-closing potential when the decoderoutput causes an LED to light.

U.S. Pat. No. 5,795,182 issued Aug. 18, 1998, discloses a polarityindependent set of battery jumper cables for jumping a first battery toa second battery. The apparatus includes a relative polarity detectorfor detecting whether two batteries are configured cross or parallel. Athree-position high current capacity crossbar pivot switch is responsiveto the relative polarity detector for automatically connecting the plusterminals of the two batteries together and the minus terminals of thetwo batteries together regardless of whether the configuration detectedis cross or parallel, and an undercurrent detector and a delay circuitfor returning the device to its ready and unconnected state after thedevice has been disconnected from one of the batteries. The crossbarpivot switch includes two pairs of contacts, and a pivot arm that pivotsabout two separate points to ensure full electrical contact between thepairs of contacts. The invention can also be used to produce a batterycharger that may be connected to a battery without regard to thepolarity of the battery.

U.S. Pat. No. 6,262,492 issued Jul. 17, 2001, discloses a car batteryjumper cable for accurately coupling an effective power source to afailed or not charged battery, which includes a relay switching circuitconnected to the power source and the battery by two current conductorpairs. First and second voltage polarity recognition circuits arerespectively connected to the power source and the battery by arespective voltage conductor pair to recognize the polarity of the powersource and the battery. A logic recognition circuit produces a controlsignal subject to the polarity of the power source and the battery, anda driving circuit controlled by the control signal from the logicrecognition circuit drives the relay switching circuit, enabling the twopoles of the power source to be accurately coupled to the two poles ofthe battery.

U.S. Pat. No. 5,635,817 issued Jun. 3, 1997, discloses a vehicle batterycharging device that includes a control housing having cables includinga current limiting device to prevent exceeding of a predeterminedmaximum charging current of about 40 to 60 amps. The control housingincludes a polarity detecting device to verify the correct polarity ofthe connection of the terminals of the two batteries and to electricallydisconnect the two batteries if there is an incorrect polarity.

U.S. Pat. No. 8,199,024 issued Jun. 12, 2012, discloses a safety circuitin a low-voltage connecting system that leaves the two low-voltagesystems disconnected until it determines that it is safe to make aconnection. When the safety circuit determines that no unsafe conditionsexist and that it is safe to connect the two low-voltage systems, thesafety circuit may connect the two systems by way of a “soft start” thatprovides a connection between the two systems over a period of time thatreduces or prevents inductive voltage spikes on one or more of thelow-voltage systems. When one of the low-voltage systems has acompletely-discharged battery incorporated into it, a method is used fordetection of proper polarity of the connections between the low-voltagesystems. The polarity of the discharged battery is determined by passingone or more test currents through it and determining whether acorresponding voltage rise is observed.

U.S. Pat. No. 5,793,185 issued Aug. 11, 1998, discloses a hand-held jumpstarter having control components and circuits to prevent overchargingand incorrect connection to batteries.

While the prior art attempted solutions to the abovementioned problemsas discussed above, each of the prior art solutions suffers from othershortcomings, either in complexity, cost or potential for malfunction.Accordingly, there exists a need in the art for further improvements tovehicle jump start devices.

SUMMARY OF THE INVENTION

In accordance with an aspect of the invention, apparatus is provided forjump starting a vehicle engine, including: an internal power supply; anoutput port having positive and negative polarity outputs; a vehiclebattery isolation sensor connected in circuit with said positive andnegative polarity outputs, configured to detect presence of a vehiclebattery connected between said positive and negative polarity outputs; areverse polarity sensor connected in circuit with said positive andnegative polarity outputs, configured to detect polarity of a vehiclebattery connected between said positive and negative polarity outputs; apower FET switch connected between said internal power supply and saidoutput port; and a microcontroller configured to receive input signalsfrom said vehicle isolation sensor and said reverse polarity sensor, andto provide an output signal to said power FET switch, such that saidpower FET switch is turned on to connect said internal power supply tosaid output port in response to signals from said sensors indicating thepresence of a vehicle battery at said output port and proper polarityconnection of positive and negative terminals of said vehicle batterywith said positive and negative polarity outputs.

In accordance with another aspect of the invention, the internal powersupply is a rechargeable lithium ion battery pack.

In accordance with yet another aspect of the invention, a jumper cabledevice is provided, having a plug configured to plug into an output portof a handheld battery charger booster device having an internal powersupply; a pair of cables integrated with the plug at one respective endthereof; said pair of cables being configured to be separately connectedto terminals of a battery at another respective end thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional block diagram of a handheld vehicle battery boostapparatus in accordance with one aspect of the present invention;

FIGS. 2A-1-2C-3 are schematic circuit diagrams of an example embodimentof a handheld vehicle battery boost apparatus in accordance with anaspect of the invention;

FIG. 3 is a perspective view of a handheld jump starter booster devicein accordance with one example embodiment of the invention; and

FIG. 4 is a plan view of a jumper cable usable with the handheld jumpstarter booster device in accordance with another aspect of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a functional block diagram of a handheld battery boosteraccording to one aspect of the invention. At the heart of the handheldbattery booster is a lithium polymer battery pack 32, which storessufficient energy to jump start a vehicle engine served by aconventional 12 volt lead-acid or valve regulated lead-acid battery. Inone example embodiment, a high-surge lithium polymer battery packincludes three 3.7V, 2666 mAh lithium polymer batteries in a 3S1Pconfiguration. The resulting battery pack provides 11.1V, 2666Ah (8000Ah at 3.7V, 29.6 Wh). Continuous discharge current is 25 C (or 200amps), and burst discharge current is 50 C (or 400 amps). The maximumcharging current of the battery pack is 8000 mA (8 amps).

A programmable microcontroller unit (MCU) 1 receives various inputs andproduces informational as well as control outputs. The programmable MCU1 further provides flexibility to the system by allowing updates infunctionality and system parameters, without requiring any change inhardware. According to one example embodiment, an 8 bit microcontrollerwith 2K×15 bits of flash memory is used to control the system. One suchmicrocontroller is the HT67F30, which is commercially available fromHoltek Semiconductor Inc.

A car battery reverse sensor 10 monitors the polarity of the vehiclebattery 72 when the handheld battery booster device is connected to thevehicle's electric system. As explained below, the booster deviceprevents the lithium battery pack from being connected to the vehiclebattery 72 when the terminals of the battery 72 are connected to thewrong terminals of the booster device. A car battery isolation sensor 12detects whether or not a vehicle battery 72 is connected to the boosterdevice, and prevents the lithium battery pack from being connected tothe output terminals of the booster device unless there is a good (e.g.chargeable) battery connected to the output terminals.

A smart switch FET circuit 15 electrically switches the handheld batterybooster lithium battery to the vehicle's electric system only when thevehicle battery is determined by the MCU 1 to be present (in response toa detection signal provided by isolation sensor 12) and connected withthe correct polarity (in response to a detection signal provided byreverse sensor 10). A lithium battery temperature sensor 20 monitors thetemperature of the lithium battery pack 32 to detect overheating due tohigh ambient temperature conditions and overextended current draw duringjump starting. A lithium battery voltage measurement circuit 24 monitorsthe voltage of the lithium battery pack 32 to prevent the voltagepotential from rising too high during a charging operation and fromdropping too low during a discharge operation.

Lithium battery back-charge protection diodes 28 prevent any chargecurrent being delivered to the vehicle battery 72 from flowing back tothe lithium battery pack 32 from the vehicle's electrical system.Flashlight LED circuit 36 is provided to furnish a flashlight functionfor enhancing light under a vehicle's hood in dark conditions, as wellas providing SOS and strobe lighting functions for safety purposes whena vehicle may be disabled in a potentially dangerous location. Voltageregulator 42 provides regulation of internal operating voltage for themicrocontroller and sensors. On/Off manual mode and flashlight switches46 allow the user to control power-on for the handheld battery boosterdevice, to control manual override operation if the vehicle has nobattery, and to control the flashlight function. The manual buttonfunctions only when the booster device is powered on. This button allowsthe user to jump-start vehicles that have either a missing battery, orthe battery voltage is so low that automatic detection by the MCU is notpossible. When the user presses and holds the manual override button fora predetermined period time (such as three seconds) to preventinadvertent actuation of the manual mode, the internal lithium ionbattery power is switched to the vehicle battery connect port. The onlyexception to the manual override is if the car battery is connected inreverse. If the car battery is connected in reverse, the internallithium battery power shall never be switched to the vehicle batteryconnect port.

USB charge circuit 52 converts power from any USB charger power source,to charge voltage and current for charging the lithium battery pack 32.USB output 56 provides a USB portable charger for charging smartphones,tablets, and other rechargeable electronic devices. Operation indicatorLEDs 60 provide visual indication of lithium battery capacity status aswell as an indication of smart switch activation status (indicating thatpower is being provided to the vehicle's electrical system).

Detailed operation of the handheld booster device will now be describedwith reference to the schematic diagrams of FIGS. 2A-1-2C-3. As shown inFIG. 2A-2, the microcontroller unit 1 is the center of all inputs andoutputs. The reverse battery sensor 10 comprises an optically coupledisolator phototransistor (4N27) connected to the terminals of vehiclebattery 72 at input pins 1 and 2 with a diode D8 in the lead conductorof pin 1 (associated with the negative terminal CB−), such that if thebattery 72 is connected to the terminals of the booster device with thecorrect polarity, the optocoupler LED 11 will not conduct current, andis therefore turned off, providing a “1” or high output signal to theMCU 1. The car battery isolation sensor 12 comprises an opticallycoupled isolator phototransistor (4N27) connected to the terminals ofvehicle battery 72 at input pins 1 and 2 with a diode D7 in the leadconductor of pin 1 (associated with the positive terminal CB+), suchthat if the battery 72 is connected to the terminals of the boosterdevice with the correct polarity, the optocoupler LED 11A will conductcurrent, and is therefore turned on, providing a “0” or low outputsignal to the MCU, indicating the presence of a battery across thejumper output terminals of the handheld booster device.

If the car battery 72 is connected to the handheld booster device withreverse polarity, the optocoupler LED 11 of the reverse sensor 10 willconduct current, providing a “0” or low signal to microcontroller unit1. Further, if no battery is connected to the handheld booster device,the optocoupler LED 11A of the isolation sensor 12 will not conductcurrent, and is therefore turned off, providing a “1” or high outputsignal to the MCU, indicating the absence of any battery connected tothe handheld booster device. Using these specific inputs, themicrocontroller software of MCU 1 can determine when it is safe to turnon the smart switch FET 15, thereby connecting the lithium battery packto the jumper terminals of the booster device. Consequently, if the carbattery 72 either is not connected to the booster device at all, or isconnected with reverse polarity, the MCU 1 can keep the smart switch FET15 from being turned on, thus prevent sparking/short circuiting of thelithium battery pack.

As shown in FIG. 2B-2, the FET smart switch 15 is driven by an output ofthe microcontroller 1. The FET smart switch 15 includes three FETs (Q15,Q18, and Q19) in parallel, which spreads the distribution of power fromthe lithium battery pack over the FETs. When that microcontroller outputis driven to a logic low, FETs 16 are all in a high resistance state,therefore not allowing current to flow from the internal lithium batterynegative contact 17 to the car battery 72 negative contact. When themicro controller output is driven to a logic high, the FETs 16 (Q15,Q18, and Q19) are in a low resistant state, allowing current to flowfreely from the internal lithium battery pack negative contact 17 (LB−)to the car battery 72 negative contact (CB−). In this way, themicrocontroller software controls the connection of the internal lithiumbattery pack 32 to the vehicle battery 72 for jumpstarting the carengine.

Referring back to FIG. 2A-1, the internal lithium battery pack voltagecan be accurately measured using circuit 24 and one of theanalog-to-digital inputs of the microcontroller 1. Circuit 24 isdesigned to sense when the main 3.3V regulator 42 voltage is on, and toturn on transistor 23 when the voltage of regulator 42 is on. Whentransistor 23 is conducting, it turns on FET 22, thereby providingpositive contact (LB+) of the internal lithium battery a conductive pathto voltage divider 21 allowing a lower voltage range to be brought tothe microcontroller to be read. Using this input, the microcontrollersoftware can determine if the lithium battery voltage is too low duringdischarge operation or too high during charge operation, and takeappropriate action to prevent damage to electronic components.

Still referring to FIG. 2A-1, the temperature of the internal lithiumbattery pack 32 can be accurately measured by two negative temperaturecoefficient (NTC) devices 20. These are devices that reduce theirresistance when their temperature rises. The circuit is a voltagedivider that brings the result to two analog-to-digital (A/D) inputs onthe microcontroller 1. The microcontroller software can then determinewhen the internal lithium battery is too hot to allow jumpstarting,adding safety to the design.

The main voltage regulator circuit 42 is designed to convert internallithium battery voltage to a regulated 3.3 volts that is utilized by themicrocontroller 1 as well as by other components of the booster devicefor internal operating power. Three lithium battery back chargeprotection diodes 28 (see FIG. 2B-1) are in place to allow current toflow only from the internal lithium battery pack 32 to the car battery72, and not from the car battery to the internal lithium battery. Inthis way, if the car electrical system is charging from its alternator,it cannot back-charge (and thereby damage) the internal lithium battery,providing another level of safety. The main power on switch 46 (FIG.2A-1) is a combination that allows for double pole, double throwoperation so that with one push, the product can be turned on if it isin the off state, or turned off if it is in the on state. This circuitalso uses a microcontroller output 47 to “keep alive” the power when itis activated by the on switch. When the switch is pressed themicrocontroller turns this output to a high logic level to keep power onwhen the switch is released. In this way, the microcontroller maintainscontrol of when the power is turned off when the on/off switch isactivated again or when the lithium battery voltage is getting too low.The microcontroller software also includes a timer that turns the poweroff after a predefined period of time, (such as, e.g. 8 hours) if notused.

The flashlight LED circuit 45 shown in FIG. 2B-3 controls the operationof flashlight LEDs. Two outputs from the microcontroller 1 are dedicatedto two separate LEDs. Thus, the LEDs can be independentlysoftware-controlled for strobe and SOS patterns, providing yet anothersafety feature to the booster device. LED indicators provide thefeedback the operator needs to understand what is happening with theproduct. Four separate LEDs 61 (FIG. 2A-3) are controlled bycorresponding individual outputs of microcontroller 1 to provideindication of the remaining capacity of the internal lithium battery.These LEDs are controlled in a “fuel gauge” type format with 25%, 50%,75% and 100% (red, red, yellow, green) capacity indications. An LEDindicator 63 (FIG. 2B-4) provides a visual warning to the user when thevehicle battery 72 has been connected in reverse polarity. “Boost” andon/off LEDs 62 provide visual indications when the booster device isprovide jump-start power, and when the booster device is turned on,respectively.

A USB output 56 circuit (FIG. 2C-1) is included to provide a USB outputfor charging portable electronic devices such as smartphones from theinternal lithium battery pack 32. Control circuit 57 from themicrocontroller 1 allows the USB Out 56 to be turned on and off bysoftware control to prevent the internal lithium battery getting too lowin capacity. The USB output is brought to the outside of the device on astandard USB connector 58, which includes the standard voltage dividerrequired for enabling charge to certain smartphones that require it. TheUSB charge circuit 52 allows the internal lithium battery pack 32 to becharged using a standard USB charger. This charge input uses a standardmicro-USB connector 48 allowing standard cables to be used. The 5Vpotential provided from standard USB chargers is up-converted to the12.4VDC voltage required for charging the internal lithium battery packusing a DC-DC converter 49. The DC-DC converter 49 can be turned on andoff via circuit 53 by an output from the microcontroller 1.

In this way, the microcontroller software can turn the charge off if thebattery voltage is measured to be too high by the A/D input 22.Additional safety is provided for helping to eliminate overcharge to theinternal lithium battery using a lithium battery charge controller 50that provides charge balance to the internal lithium battery cells 51.This controller also provides safety redundancy for eliminating overdischarge of the internal lithium battery.

FIG. 3 is a perspective view of a handheld device 300 in accordance withan exemplary embodiment of the invention. 301 is a power on switch. 302shows the LED “fuel gauge” indicators 61. 303 shows a 12 volt outputport connectable to a cable device 400, described further below. 304shows a flashlight control switch for activating flashlight LEDs 45. 305is a USB input port for charging the internal lithium battery, and 306is a USB output port for providing charge from the lithium battery toother portable devices such as smartphones, tablets, music players, etc.307 is a “boost on” indicator showing that power is being provided tothe 12V output port. 308 is a “reverse” indicator showing that thevehicle battery is improperly connected with respect to polarity. 309 isa “power on” indicator showing that the device is powered up foroperation.

FIG. 4 shows a jumper cable device 400 specifically designed for usewith the handheld device 300. Device 400 has a plug 401 configured toplug into 12 volt output port 303 of the handheld device 300. A pair ofcables 402 a and 402 b are integrated with the plug 401, and arerespectively connected to battery terminal clamps 403 a and 403 b viaring terminals 404 a and 404 b. The port 303 and plug 401 may bedimensioned so that the plug 401 will only fit into the port 303 in aspecific orientation, thus ensuring that clamp 403 a will correspond topositive polarity, and clamp 403 b will correspond to negative polarity,as indicated thereon. Additionally, the ring terminals 404 a and 404 bmay be disconnected from the clamps and connected directly to theterminals of a vehicle battery. This feature may be useful, for example,to permanently attach the cables 302 a-302 b to the battery of avehicle. In the event that the battery voltage becomes depleted, thehandheld booster device 300 could be properly connected to the batteryvery simply by plugging in the plug 401 to the port 303.

The invention having been thus described, it will be apparent to thoseskilled in the art that the same may be varied in many ways withoutdeparting from the spirit or scope of the invention. Any and all suchvariations are intended to be encompassed within the scope of thefollowing claims.

What is claimed is:
 1. A jumper cable device, comprising: a plugconfigured to plug into an output port of a handheld battery chargerbooster device having an internal power supply; a pair of cablesintegrated with the plug at one respective end thereof; said pair ofcables being configured to be separately connected to terminals of abattery at another respective end thereof.
 2. The jumper cable device ofclaim 1, further comprising a pair of ring terminals configured torespectively connect said pair of cables at said another end thereofwith one of a battery terminal, or a battery terminal clamp.
 3. Thejumper cable device of claim 1, wherein said output port and said plugare dimensioned so that the plug will fit into the output port only inone specific orientation.
 4. A jumper cable device, comprising: a plugconfigured to plug into an output port of a handheld battery chargerbooster device having an internal power supply; a pair of cablesintegrated with the plug at one respective end thereof; and a pair ofbattery terminal clamps respectively connected with said pair of cablesat another respective end thereof.